1. Field of the Invention
The present invention relates to a printing control apparatus which spools a plurality of print data transmitted from a host computer and controls print processing, and a control method therefor.
2. Description of the Related Art
There is a user demand to print one more copy of a given document after printing the given document. To meet this demand, there is known a technique of printing a document in accordance with an instruction to print again (to be referred to as reprint hereinafter) from the operation panel of an image forming apparatus without retransmitting print data from a host computer to the image forming apparatus (for example, Japanese Patent Laid-Open No. 2001-063158).
In normal print processing, an image forming apparatus stores a print job received from the host computer in the internal storage of the image forming apparatus, and after the end of print processing, deletes the stored print job. To the contrary, an image forming apparatus having the above-mentioned reprint function keeps storing received print jobs until the free space of the storage runs out, without deleting stored print jobs even after the end of print processing. The user can reprint a printed image by only inputting a reprint instruction from the operation panel of the image forming apparatus without retransmitting print data from the host computer.
Some image forming apparatuses require user authentication to operate them, and others do not require it. When the reprint function is used in an image forming apparatus which does not perform user authentication, a print job stored in accordance with a print instruction from a given user can be reprinted in accordance with a reprint instruction from a user (another person) different from the given user. Depending on the contents of a reprint instruction, a print job can be reprinted by a plurality of copies. A user may not permit another person to print even a less confidential document.
To prevent printing of a print job by another person without permission when an image forming apparatus operates in the reprint mode, there is proposed a technique of controlling execution of reprinting by user authentication (for example, Japanese Patent Laid-Open No. 2008-183889).
In the technique of Japanese Patent Laid-Open No. 2008-183889, when printing a document stored in a removable medium such as a USB memory, a user is requested to input authentication information, and the input authentication information and raster data generated from the document are stored as a reprint job in an internal memory. Upon receiving an instruction to print the stored reprint job, the user is authenticated according to the authentication information stored in association with the reprint job. Only when the user authentication is successful, reprinting is executed. Before the first printing, this technique prompts the user to determine whether to store a reprint job securely (not to print it by another person without permission). Only when the user instructs to store a reprint job securely, is raster data stored together with authentication information. However, it is required to always store a reprint job securely in printing and prevent printing of the reprint job by another person in reprinting without being aware by the user of whether to store it securely.